Show phone numbers associated with each line rather than ext

Hello I have a yealink T27G installed with Ooma Office with 2 phone lines - anyone know how I can show the
two lines separately on the view screen next to the buttons that select a line? The screen just shows my extension net to the buttons and not the numbers for the separate lines. I would like to leave line 1 free for incoming calls and just use line 2 for outgoing calls.
thanks for any help
Colin

I 'd to learn it too.